fix(config): don't pick a write target that config loading ignores

[JamBalaya56562]

Summary

mise use can pick a write target that config loading deliberately skips, so the tool it writes is never read back.

The two write-target resolvers are separate implementations of the same rule, and only one was kept current. The exclusion added for #7015 — which drops configs under the default ~/.config/mise once MISE_CONFIG_DIR points elsewhere — is reached through config_path_is_ignored, and only local_toml_config_path_from_dir calls it. config_file_from_dir applies just !is_global_config(cf).

With a relocated config dir, config_file_from_dir walks up to $HOME, finds ~/.config/mise/config.toml (a recognised local config filename), no longer recognises it as the global config, and returns it.

$ export MISE_CONFIG_DIR=/root/alt/mise

$ mise config ls
~/alt/mise/config.toml                          # the default location is excluded, as #7015 intends

$ mise use --dry-run uv@0.12.0
mise would update ~/.config/mise/config.toml    # ...but that is where the tool goes

Measured on v2026.7.15 and v2026.7.18, Linux and Windows alike. mise set is unaffected — it goes through the resolver that has the filter.

What changed

The shared walk is extracted into nearest_local_config_file(start, filenames), and both resolvers use it. That is local_toml_config_path_from_dir's existing body with the filename list and the walk root as parameters, so each caller keeps its own filenames and its own fallback (config_file_from_dir keeps the asdf_compat one).

• mise set and friends: no behaviour change. Same filenames, same walk root, same fallback.
• mise use: gains the four filters it was missing — the MISE_NO_CONFIG short-circuit, config_dir_is_ignored, the desymlink dedupe, and config_path_is_ignored.

That last point is worth calling out because it is broader than the bug above: mise use now also honours MISE_IGNORED_CONFIG_PATHS and MISE_NO_CONFIG when choosing where to write, which it arguably should have all along and which mise set already did. Happy to narrow this to only the #7015 filter if you would rather keep the change minimal.

config_file_from_dir still walks from env::current_dir() rather than from its p argument. That is pre-existing and affects use --path / unuse --path, so I left it alone here.

Tests

e2e/cli/test_config_dir_override is the test written for #7015 and only covered reads. It now also asserts the write target, plus a pin on mise set since it shares the resolver now.

Verified locally on Windows against the released v2026.7.18 binary; every case below matches except the first, which is the bug:

	v2026.7.18	this PR
use, MISE_CONFIG_DIR relocated, no local config	~/.config/mise/config.toml	./mise.toml
use, config-less deep dir	plain/deep/mise.toml	same
use, ancestor has mise.toml	anc/mise.toml	same
use, mise.toml + mise.local.toml	both/mise.toml	same
use -g	<config dir>/config.toml	same
set, nested dirs	anc/mise.toml	same
set, lowest-precedence file	both/mise.toml	same
set, MISE_IGNORED_CONFIG_PATHS	anc/x/y/mise.toml	same

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Configuration changes made with mise use and mise set are now written to the nearest valid local configuration file.
  • Prevented updates from being written to excluded default configuration files.
  • Improved consistency when resolving local configuration files across directories, symlinks, and ignored paths.
• Tests
  • Expanded end-to-end coverage to verify configuration write behavior.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Central YAML (base), Organization UI (inherited)

Review profile: CHILL

Plan: Pro Plus

Run ID: a8365bba-8ec3-4a5e-a7db-ae918d28caef

📥 Commits

Reviewing files that changed from the base of the PR and between 7ae90ff and c5c283f.

📒 Files selected for processing (2)

• e2e/cli/test_config_dir_override
• src/config/mod.rs

🚧 Files skipped from review as they are similar to previous changes (2)

• src/config/mod.rs
• e2e/cli/test_config_dir_override

---

📝 Walkthrough

Walkthrough

The change centralizes nearest local configuration-file resolution and updates both configuration lookup paths to use it. The end-to-end test verifies that mise use and mise set write to the local configuration while leaving the default configuration unchanged.

Changes

Local configuration resolution

Layer / File(s)	Summary
Shared local configuration resolver src/config/mod.rs	Added nearest_local_config_file for upward local configuration discovery. It skips ignored paths, deduplicates symlink-equivalent files, applies precedence, and excludes global files. Both configuration lookup paths use the resolver.
Write-target end-to-end validation e2e/cli/test_config_dir_override	Added checks that mise use and mise set write to the local mise.toml and do not modify the default configuration.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Possibly related PRs

• jdx/mise#11103: Both changes modify configuration discovery and precedence logic in src/config/mod.rs.
• jdx/mise#11575: Both changes modify directory-local configuration resolution in src/config/mod.rs.

Poem

A rabbit checks the config trail,
As nearest local paths prevail.
mise use writes close at hand,
mise set leaves the default unchanged.
TOML rests in its proper place.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main fix: preventing write targets that configuration loading ignores.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[greptile-apps]

Greptile Summary

The PR consolidates local configuration write-target discovery so mise use and mise set avoid configuration files that loading deliberately ignores.

• Extracts the shared nearest-local-config traversal and filtering logic.
• Applies the existing ignore-path, ignore-directory, symlink-deduplication, and no-config handling to mise use.
• Extends the configuration-directory override test to cover write targets for both commands.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

Important Files Changed

Filename	Overview
src/config/mod.rs	Extracts the existing local TOML resolver and reuses it for the broader write-target resolver while retaining each caller's filename set and fallback behavior.
e2e/cli/test_config_dir_override	Adds isolated end-to-end assertions that relocated configuration directories do not cause mise use or mise set to modify the ignored default config.

_{Reviews (2): Last reviewed commit: "fix(config): don't pick a write target t..." | Re-trigger Greptile}